If the trillion-dollar war on drugs has failed to put a dent in substance abuse, perhaps a viewing of "Magic Trip" will succeed.

This documentary (subtitled "Ken Kesey's Search for a Kool Place") attempts to assemble archival footage shot by Kesey and his Merry Pranksters on their legendary cross-country trip from California to the New York World's Fair in 1967.

Ace documentarian Alex Gibney is the editor/director. He could make sense of the torture debate ("Taxi to the Dark Side"). He could make sense of the Enron scandal ("The Smartest Guys in the Room"). But he can make no sense of the footage left him by the drug-addled Pranksters.

Gibney's interviews with survivors tell you why - participants were taking as much LSD and speed as they could, then grabbing the camera with their palsied mitts and pointing the lens at anything that moved. Or at anything they thought was moving.

Seemed like a super-groovy idea at the time, I'm sure. Watching it today is like walking into a room full of high people and trying follow their . . . whimsical conversations.

Even some of the riders gave up in terror, or out of boredom. One took too much acid and ran screaming into the night in her PJs. Others just got tired of the dead-end scene and left.

What put them off? One factor could have been Neal Cassady's nonstop talking. Cassady, of course, is famous as the model for Moriarty in Jack Kerouac's "On The Road." Here he's the bus driver. Pranksters rhapsodize about Cassady's stream-of-consciousness narrative at the wheel. "Magic Trip" allows you to hear it for yourself. It's gibberish.

You understand why there were defections and early exits. And if the bus were not tolerable to certain members of the entourage, it was highly intolerable to outsiders. One telling scene shows the bus pulling into the driveway of one prankster's old Army buddy. A shot of the man's face shows how eager he is for them to leave.

Also not a fan - Timothy Leary. The Pranksters arrive at Leary's '60s acid compound in New York expecting a sympathetic reception, only to discover that Leary heads a cult of standoffish drug snobs. His followers seek enlightenment and higher consciousness, and regard the party-minded Pranksters as low-class interlopers.

Neither group is alert to potential dangers, and the movie treats drug use as a lark. Kesey's before-and-after footage tells a different story. He devolves from a handsome, talented man of letters to the warm-up act for '60s nostalgia gigs - a confused, elderly gent trying to explain why he hasn't finished a novel in 30 years.

He argues (as a youthful prankster) that film is superior to the written word. Words, he says, can only remove us from observed truth. Kesey's own footage proves him wrong. His botched movie (he could never finish it) counterargues for the value of the well-turned phrase. As do "One Flew Over the Cuckoo's Nest" and "Sometimes a Great Notion."

Maybe, a gray-haired Kesey wonders at last, his critics were right. Maybe the LSD really did fry his brain.